Water circulation apparatus associated with refrigerant system

ABSTRACT

A water circulation apparatus performs a variety of heat exchange operations for various refrigerants. The apparatus may be applied for a first refrigerant system having a first compressor and first heat-exchanger and a second refrigerant system having a second compressor. An intermediate heat-exchanger performs heat-exchange operations between first and second refrigerants flowing in respective ones of the systems. A water circulator is then used to circulate water which is heat-exchanged with the second refrigerant while the water is circulated. The apparatus performs these functions for operating modes which include a heating mode and a cooling mode. Defrosting operations are also performed for one or more of the heat exchangers.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 USC §119 and 35 USC 365to Korean Patent Application No. 10-2009-0123571, filed on Dec. 11,2009, which is hereby incorporated by reference in its entirety.

BACKGROUND

1. Field

One or more embodiments herein relate to cooling and/or heating systems.

2. Background

Refrigerant systems perform heat-exchanging operations for various typesof household and commercial applications. Many related-art systems haveproven to be inefficient and ineffective, especially when it comes todefrosting the heat exchangers and the ability to provide heat or heatedwater when, for example, temperatures are very low in the surroundingenvironment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of one embodiment of a water circulation apparatusassociated with a refrigerant system.

FIG. 2 is a flowchart showing steps in a first embodiment of adefrosting method using a water circulation apparatus associated with arefrigerant system.

FIG. 3 is a flowchart showing steps included in a second embodiment of adefrosting method for a water circulation apparatus associated with arefrigerant system.

FIG. 4 is a flowchart showing steps included in a third embodiment of adefrosting method for a water circulation apparatus associated with arefrigerant system.

FIG. 5 is a flowchart showing steps included in a fourth embodiment of adefrosting method for a water circulation apparatus associated with arefrigerant system.

FIG. 6 is a diagram of another embodiment of a water circulationapparatus associated with a refrigerant system.

FIG. 7 is a flowchart showing steps included in another embodiment of adefrosting method for a water circulation apparatus associated with arefrigerant system.

FIG. 8 is a diagram of another embodiment of a water circulationapparatus associated with a refrigerant system.

DETAILED DESCRIPTION

FIG. 1 shows one embodiment of a water circulation apparatus whichincludes a first refrigerant system 1, a second refrigerant system 2, ahot water supply part 4, and a cooling/heating part 5. The firstrefrigerant system controls a first refrigerant cycle for circulating afirst refrigerant. The second refrigerant system controls a secondrefrigerant cycle for circulating a second refrigerant, and performs anoperation in which the first refrigerant is heat-exchanged with a secondrefrigerant and then a heat-exchange operation is performed between thesecond refrigerant and water. The hot water supply part is connected tothe second refrigerant system to supply hot water, and thecooling/heating part is connected to the second refrigerant system toheat and cool, for example, an indoor room.

The first refrigerant system 1 includes a first compressor 11 forcompressing the first refrigerant, a first four-way valve 12 forregulating a flow direction of the first refrigerant discharged from thefirst compressor, an intermediate heat-exchanger 25 in which the firstrefrigerant is heat-exchanged with the second refrigerant, a firstexpansion part 14 for expanding the first refrigerant, and a firstheat-exchanger 13 in which the first refrigerant is heat-exchanged withoutdoor air. The first compressor, the first four-way valve, theintermediate heat-exchanger, first expansion part, and firstheat-exchanger are connected to each other through a first refrigerantpipe 15.

In this embodiment, because the intermediate heat-exchanger performs aheat-exchange operation between the first and second refrigerants, theintermediate heat-exchanger may be referred to as arefrigerant-refrigerant heat-exchanger. Also, while FIG. 1 shows thatthe intermediate heat-exchanger lies outside of system 1, in otherembodiments the intermediate heat-exchanger may be included within thebox corresponding to the first refrigerant system.

The second refrigerant system 2 includes a second compressor 21 forcompressing the second refrigerant, a second four-way valve 22regulating a flow direction of the second refrigerant discharged fromthe second compressor, a second heat-exchanger 23 for performing aheat-exchange operation between the second refrigerant and water, asecond expansion part 24 for expanding the second refrigerant, and theintermediate heat-exchanger 25 previously mentioned for performing theheat-exchange operation between the first refrigerant and the secondrefrigerant.

The second compressor 21, second four-way valve 22, secondheat-exchanger 23, second expansion part 24, and intermediateheat-exchanger 25 are connected to each other through a secondrefrigerant pipe 26. In this embodiment, since the second heat-exchanger23 performs a heat-exchange operation between the second refrigerant andwater, the second heat-exchanger may be referred to as awater-refrigerant heat-exchanger.

The intermediate heat-exchanger 25 includes a first passage 251 throughwhich the first refrigerant flows and a second passage 252 through whichthe second refrigerant flows. The first passage and second passage maybe defined by or included as part of the first refrigerant pipe 15 andthe second refrigerant pipe 26, respectively.

Alternatively, separate first and second passages 251 and 252 may bedefined in the intermediate heat-exchanger 25. In such an arrangement,the first refrigerant pipe 15 may be connected to the first passage 251and the second refrigerant pipe 26 may be connected to the secondpassage 252.

The second heat-exchanger 23 includes a refrigerant passage 231 throughwhich the second refrigerant flows and a water passage 232 through whichwater flows. The refrigerant passage and water passage may be defined byor included as part of the second refrigerant pipe 26 and a first waterpipe 30 respectively. Also, in accordance with one or more embodiments,a plate heat-exchanger may be used as or included in intermediateheat-exchanger 25 and the second heat-exchanger 23, but variations arepossible.

The intermediate heat-exchanger 25 may be disposed within a first case(not shown) including the first refrigerant system 1 or a second case(not shown) including the second refrigerant system 2. Also, the firstand second refrigerant systems may be disposed within a single case.

In one embodiment, for example, R410 a may be used as the firstrefrigerant and R134 a may be used as the second refrigerant. That is,the first refrigerant of the first refrigerant system is different fromthe second refrigerant of the second refrigerant system.

When the first refrigerant system is operated in heating mode, the firstrefrigerant compressed by first compressor 11 flows into intermediateheat-exchanger 25 by the flow regulation of first four-way valve 12. Thefirst refrigerant flowing into the intermediate heat-exchanger isheat-exchanged with the second refrigerant, and then flows into firstexpansion part 14. The first refrigerant is expanded by the firstexpansion part and evaporated while it flows into first heat-exchanger13.

The evaporated first refrigerant is then introduced into firstcompressor 11. That is, when the first refrigerant system is operated inheating mode, the second refrigerant compressed by second compressor 21flows into second heat-exchanger 23 by flow regulation performed bysecond four-way valve 22.

The second refrigerant flowing into second heat-exchanger 23 isheat-exchanged with water and then flows into second expansion part 24.Then, the second refrigerant is expanded by second expansion part 24 andevaporated by being heat-exchanged with the first refrigerant while itflows into the intermediate heat-exchanger 25. The evaporated secondrefrigerant is introduced into second compressor 21. That is, when thesecond refrigerant system operates in heating mode, intermediateheat-exchanger 25 serves as an evaporator with respect to the secondrefrigerant system.

In FIG. 1, a solid arrow line indicates a flow of refrigerant when therefrigerant systems operate in heating mode, and a dotted arrow lineindicates a flow of refrigerant when the refrigerant systems operate incooling mode.

In summary, when refrigerant systems 1 and 2 operate in heating mode,the intermediate heat exchanger 25 serves as a condenser with respect tothe first refrigerant system 1 and an evaporator with respect to thesecond refrigerant system 2. Thus, if the first refrigerant systemoperates in cooling mode and the second refrigerant system operates inheating mode, the intermediate heat-exchanger may serve as theevaporator with respect to each of the refrigerant systems 1 and 2.

In FIG. 1, the first and second refrigerants are shown as having thesame flow direction in intermediate heat-exchanger 25 when therefrigerant systems are operating in heating mode. However, in otherembodiments, the first and second refrigerants may flow in oppositedirections by changing the connection positions of the refrigerantpipes.

The second refrigerant system 2 may also include a water flow devicewhich includes first water pipe 30, a flow switch 32 disposed in thefirst water flow pipe to detect water flow, an expansion tank 33branched at a predetermined position spaced from the flow switch in anwater flow direction, a water collection tank 34 in which a portion ofthe first water pipe is inserted and which includes an auxiliary heater35 therein, and a water pump 36 disposed at a predetermined position ofa second water pipe 61 disposed at an outlet-side of the watercollection tank.

The first water pipe 30 includes an inlet pipe at an inlet-side ofsecond heat-exchanger 23, an outlet pipe 302 disposed at an outlet-sideof the second heat-exchanger 23, and a branch pipe branched from theinlet pipe 301 and joint at the outlet pipe 302. The outlet pipe 302 isconnected to the water collection tank 34. A water pump 310 for pumpingthe water is disposed on the inlet pipe 301. In this embodiment, aninverter pump that can regulate an amount of the pumped water may beused as water pumps 36 and 310.

The intermediate heat-exchanger 25 further includes a water passage 253in which the water branched from inlet pipe 301 flows. That is, theintermediate heat-exchanger includes first refrigerant passage 251,second refrigerant passage 252, and water passage 253. The firstrefrigerant of the first refrigerant passage 251 is heat-exchanged withthe second refrigerant of second refrigerant passage 252, and water ofthe water passage 253 is heat-exchanged with the first refrigerant ofthe first refrigerant passage 251.

On the other hand, water of water passage 253 may be heat-exchanged withthe second refrigerant of second refrigerant passage 252, or water ofthe water passage 253 may be respectively heat-exchanged with the firstrefrigerant and the second refrigerant. However, to heat the water ofwater passage 253, the water passage may be disposed such that the waterand the first refrigerant may be sufficiently heat-exchanged.

At this time, a passage extending from inlet pipe 301 to outlet pipe 302via second heat-exchanger 23 may be referred to as a main passage. Also,a passage branched from the inlet pipe and extending to the outlet pipevia intermediate heat-exchanger 25 may be referred to as a sub passage.Although branch pipe 303 is connected to outlet pipe 302 in thisembodiment, the branch pipe may be directly connected to watercollection tank 34 without being connected to outlet pipe 302.

Valves 304 and 305 for regulating a flow amount of the water aredisposed on inlet- and outlet-side pipes of heat-exchanger 25 of thebranch pipe 303, respectively.

When the second refrigerant system is operated in heating mode, heat QHwith a high temperature is transmitted from the second refrigerantdischarged from second compressor 21 and into water flowing along waterpassage 232. When heat is transmitted into water passage 232, waterflowing in water passage 232 increases in temperature.

As the water is heated while it passes through the second heat-exchanger23, it expands to a volume greater than a reasonable volume. Theexpansion tank 33, therefore, is provided to perform a buffer function.A diaphragm (not shown) may be disposed within the expansion tank tomove corresponding to variations in volume of the water of the outletpipe 302, and a nitrogen gas may be filled into the expansion tank 33.

The water collection tank 34 stores water supplied from the outlet pipe,and auxiliary heater 35 may be operated when the water has a temperatureless than a required temperature is disposed within the water collectiontank 34.

An air vent 343 is used to exhaust heated air within the watercollection tank 34 and may be disposed in water collection tank 34.Also, a pressure gauge 341 and a valve 342 for regulating a pressurewithin the water collection tank may be disposed in the water collectiontank. For example, when the pressure within water collection tank 35 asdetected by pressure gauge 341 is excessively high, valve 342 may beopened to decrease the pressure within the water collection tank.

The water pump 36 pumps water from the water collection tank into secondwater pipe 61. The water pumped into the second water pipe may besupplied to the hot water supply part 4 or the cooling/heating part 5.The hot water supply part 4 heats and supplies water required, forexample, for wash up of a user (e.g., a bath or shower) or dish-washingpurposes.

More specifically, a three-way valve 71 for regulating a flow directionof water of second water pipe 61 may be disposed in the second waterpipe. The water pumped by pump 36 flows into hot water supply partand/or cooling/heating part by three-way valve 71.

As a result, hot water supply pipe 62 extending to hot water supply part4 and cooling/heating pipe 63 extending to cooling/heating part 5 areconnected to an outlet-side of the three-way valve. The water pumped bywater pump 36 flows into the hot water supply pipe 62 and/or thecooling/heating pipe 63 under the control of three-way valve 71.

The hot water supply part 4 includes a hot water supply tank 41 forstoring water supplied from the outside and for heating the stored waterand an auxiliary heater 42 disposed within the hot water supply tank.Also, an auxiliary heat source supplying heat to the hot water supplytank 41 may be further disposed according to an installationconfiguration. A thermal storage tank using solar heat may be used as anauxiliary heater. The hot water supply tank 41 includes a water inflowpart 411 through which water is introduced and a water discharge part412 through which heated water is discharged.

More specifically, a portion of hot water supply pipe 62 extending fromthree-way valve 71 is inserted into hot water supply tank 41 to heat thewater stored in the hot water supply tank. That is, heat is transmittedfrom the hot water flowing into the hot water supply pipe 62 to thewater stored in hot water supply tank 41. In some cases, auxiliaryheater 42 and the auxiliary heat source may be operated to additionallysupply heat to the water stored in hot water supply tank 41.

For example, when a large amount of hot water is required for the user'sbath, since water should be heated in a short period of time, auxiliaryheater 42 or the auxiliary heat source may be operated. A temperaturesensor 414 may be disposed at one side of the hot water supply tank fordetecting water temperature in this regard.

As necessary, hot water discharge device such as a shower 45 or anelectric device such as a humidifier may be connected to the waterdischarge part 412. When the thermal storage tank 43 using the solarheat is used as the auxiliary heat source, a thermal storage pipe 47extending from the thermal storage tank may be inserted into the hotwater supply tank 41. An auxiliary pump 44 for controlling a flowvelocity within a thermal storage pipe close loop may be disposed on thethermal storage pipe 47. Also, a solenoid valve VA for controlling aflow direction of the water within the thermal storage pipe 47 may bedisposed on the thermal storage pipe. A temperature sensor 471 formeasuring a water temperature may be disposed at a side of the thermalstorage pipe.

A structure of the auxiliary heat source such as a thermal storage partusing the solar heat is not limited to the aforementioned embodiment.For example, the auxiliary heat source may have various configurationsand be disposed at various positions.

The cooling/heating part 5 includes a floor cooling/heating unit 51 inwhich a portion of cooling/heating pipe 63 is buried in an indoor floor,and an air cooling/heating unit 52 which is branched from any positionof the cooling/heating pipe and which is connected to the floorcooling/heating unit 51 in parallel.

More specifically, as shown in FIG. 1, floor cooling/heating unit 51 maybe located under the floor in an indoor room, for example, in a meanderline-type configuration. The air cooling/heating unit 52 may include afan coil unit or a radiator. A portion of the air cooling/heating pipe54 branched from cooling/heating pipe 63 may be provided in the aircooling/heating unit as a heat-exchanging unit. Flow switching valves 55and 56 which, for example, may be incorporated in a three-way valve, maybe disposed at a position at which the air cooling/heating pipe 54 isbranched. Thus, water flowing along the cooling/heating pipe 63 may bedivided into the floor cooling/heating unit 51 and the aircooling/heating unit 52 or flow in one direction.

The hot water supply pipe 62 passing through hot water supply tank 41and the cooling/heating pipe 63 passing through the cooling/heating part5 are connected to the inlet pipe 301. A check valve V for preventingwater within any one of the hot water supply pipe 62 and thecooling/heating pipe 63 from reversely flowing may be disposed in eitheror each of the hot water supply pipe and the cooling/heating pipe.

Because the water flow device disposed in second refrigerant system 2,hot water supply part 4, and cooling/heating part 5 form a watercirculation cycle, the above-described components may be referred to asa water circulation unit.

The operation mode of the respective refrigerant systems in theforegoing embodiment may include a cooling mode, a heating mode, and adefrosting mode. The hot water supply part may control a hot watersupply mode and the cooling/heating part may control the cooling modeand the heating mode. Because the hot water supply mode of the hot watersupply part and the heating mode of the cooling/heating part are a focusin this embodiment, operations with respect to the above-described twomodes will be described.

In the hot water supply mode or the heating mode of the cooling/heatingpart, the respective refrigerant systems are operated in the heatingmode. As described above, when the respective refrigerant systems 1 and2 are operated in the heating mode, the intermediate heat-exchanger 25serves as a condenser with respect to the first refrigerant system 1 andan evaporator with respect to the second refrigerant system 2.

Thus, the second refrigerant flowing into the intermediateheat-exchanger 25 receives heat from the first refrigerant and then thesecond refrigerant increases in temperature. When the second refrigerantincreases in temperature, the second refrigerant introduced into thesecond compressor 21 increases in temperature. When the secondrefrigerant introduced into the second compressor increases intemperature, the second refrigerant discharged from the secondcompressor increases in temperature. As a result, the refrigerantflowing into second heat-exchanger 23 increases in temperature.

As a result, heat greater than that of the second refrigerant flowinginto the second heat-exchanger is transmitted to water flowing into thesecond heat-exchanger to thereby significantly increase a temperatureincrement of the water.

At this time, according to characteristics of the respectiverefrigerants, a condensing temperature of the second refrigerant (or anoutlet-side temperature of second compressor 2) is higher than that (oroutlet-side temperature of the first compressor) of the firstrefrigerant.

In case of an existing system, because water is heat-exchanged with arefrigerant of a single refrigerant system, it may be easily seen thatthe temperature increment of the water according to this system ishigher than that according to the existing system.

The temperature increase of the water heat-exchanged in the secondheat-exchanger 23 represents that the temperature of the water stored inthe water collection tank 34 increases than the water temperature of theexisting system. Thus, water having a relatively higher temperature maybe obtained, and the indoor room may be heated using the water havingthe relatively higher temperature.

Thus, according to one embodiment, water having relatively highertemperature may be obtained. Also, the cooling/heating system may bestably operated to obtain water having high temperature even when thetemperature of an associated indoor room is very low.

When the hot water supply mode is selected, water flows into the hotwater supply pipe 62 by three-way valve 71. Thus, the water flows alongthe closed loop in which second heat-exchanger 23, water collection tank34, water pump 36, three-way valve 71, and hot water supply pipe 62 areconnected to each other. In such a circulation process, the waterintroduced through water inflow part 411 of hot water supply tank 41 isheated and then discharged through water discharge part 412, therebysupplying the water to the user.

When the heating mode of cooling/heating part 5 is selected, water flowsinto cooling/heating pipe 63 by three-way valve 71. Thus, the waterflows in a closed loop that includes second heat-exchanger 23, watercollection tank 34, water tank 36, three-way valve 71, andcooling/heating pipe 63. The water flowing along cooling/heating pipe 63flows into air cooling/heating unit 52 or floor cooling/heating unit 51.

The hot water supply mode and the heating mode of the cooling/heatingpart may be selected at the same time. In this case, the water flowsinto hot water supply pipe 62 and cooling/heating pipe 63 by three-wayvalve 71.

As described above, when the respective refrigerant systems are operatedin the heating mode, the first heat-exchanger 13 of first refrigerantsystem 1 serves as an evaporator. Thus, when the first refrigerantsystem is continuously operated in the heating mode, frost may begenerated on the first heat-exchanger. Therefore, a defrosting processis required.

FIG. 2 shows operations included in one embodiment of a defrostingmethod performed for a water circulation apparatus associated with arefrigerant system, such as shown, for example, in FIG. 1.

Referring to FIGS. 1 and 2, water circulation apparatus S is operated ina mode set by a user in operation S1. Since the defrosting operation ofthe first heat-exchanger 13 is a focus of this embodiment, a case inwhich the respective refrigerant systems 1 and 2 are operated in theheating mode will be described.

When the respective refrigerant systems 1 and 2 are operated in theheating mode, branch valves 304 and 305 of branch pipe 303 are opened.Thus, one portion of water flowing into inlet pipe 301 flows into secondheat-exchanger 23 and another portion of the water flows into branchpipe 303.

The water flowing from the inlet pipe to second heat-exchanger 25 isheat-exchanged with the second refrigerant, and the water branched bybranch pipe 303 is heat-exchanged with the first refrigerant inintermediate heat-exchanger 25. At this time, it may be easily seen thata temperature of the water heat-exchanged with the second refrigerant isgreater than that of the water heat-exchanged with the firstrefrigerant.

In operation S2, it is determined whether a defrosting operationcondition is satisfied during the preset mode of water circulationapparatus S. Whether the defrosting condition is satisfied may bedetermined, for example, by comparing a temperature of a pipeoutlet-side of first heat-exchanger 13 to an indoor room temperature. Inother embodiments, satisfaction of the defrosting condition may bedetermined using other techniques.

According to the determination result in operation S2, when thedefrosting condition is satisfied, first refrigerant system 1 isoperated in defrosting mode in operation S3, and second refrigerantsystem 2 is maintained in a present operation mode (e.g., heating mode).In this embodiment, when the first refrigerant system is operated indefrosting mode regardless of the operation mode of the secondrefrigerant system, the water circulation apparatus is operated in thedefrosting mode.

In this embodiment, a state in which the first refrigerant system isoperated in defrosting mode represents a state in which the firstrefrigerant system is operated in the cooling mode.

When the first refrigerant system is operated in defrosting mode,intermediate heat-exchanger 25 serves as an evaporator with respect torefrigerant systems 1 and 2, and the first heat-exchanger serves as acondenser for the refrigerant systems. Thus, during defrosting mode ofthe first refrigerant system, a defrosting operation of firstheat-exchanger 13 is performed based on high temperature refrigerantflowing into the first heat-exchanger.

At this time, because intermediate heat-exchanger 25 serves as theevaporator with respect to the refrigerant systems, low temperaturerefrigerants are heat-exchanged with each other to reduce vaporpressures of the respective refrigerant systems. Thus, cycleperformances of the refrigerant systems may deteriorate and theirrespective compressors may be damaged.

To prevent the vapor pressures of the refrigerant systems from beingreduced, during the defrosting mode of the first refrigerant system thebranch valves 304 and 305 are closed in operation S4. Thus, water doesnot flow into branch pipe 303 and the first refrigerant isheat-exchanged with the hot water within the branch pipe. Since thefirst refrigerant heat-exchanged with the hot water is heat-exchangedwith the second refrigerant, each of the refrigerants may increase intemperature to minimize the reduction of the vapor pressures of therefrigerant systems.

In operation S5, it is determined whether the defrosting operation isfinished during the defrosting mode of the first refrigerant system.

In operation S6, when the defrosting operation is finished, the closedbranch valves 304 and 305 are opened.

In operation S7, the first refrigerant system is operated in theprevious mode. As a result, the first refrigerant system is operated inthe heating mode.

According to this embodiment, during the defrosting mode of the firstrefrigerant system, because the second refrigerant system is operated inthe heating mode, the hot water may be obtained and the indoor room maybe heated using the hot water. Also, because the hot water isheat-exchanged with the first refrigerant flowing into intermediateheat-exchanger 25 to increase a temperature of the first refrigerant,the reduction of the vapor pressures of the respective refrigerantsystems may be minimized. Thus, the performance deterioration of therespective refrigerant systems may be minimized.

FIG. 3 shows operations in a second embodiment of a defrosting method.The second embodiment is similar to the first embodiment except foroperation of a branch valve. Referring to FIGS. 1 and 3, a watercirculation apparatus according to the second embodiment is operated ina mode set by a selection of a user in operation S11. Since a defrostingoperation of first heat-exchanger 13 is a focus in this embodiment, acase in which refrigerant systems operate in a heating mode will bedescribed.

When refrigerant systems 1 and 2 operate in heating mode, branch valves304 and 305 of a branch pipe 303 are closed. Thus, all water flowinginto an inlet pipe 301 flows into a second heat-exchanger 23 toheat-exchange with a second refrigerant. When the second refrigerantsystem 2 operate in heating mode, water flowing into inlet pipe 301 andwater flowing into outlet pipe 303 continuously increase in temperature.

In operation S12, it is determined whether a defrosting condition issatisfied when water circulation apparatus S is operated in the setmode. According to the determination result in operation S12, when thedefrosting operation condition is satisfied, first refrigerant system 1is operated in defrosting mode, and the second refrigerant system ismaintained in the present operation mode (the heating mode).

When the first refrigerant system operates in the defrosting mode,intermediate heat-exchanger 25 serves as an evaporator with respect tothe refrigerant systems, and the first heat-exchanger serves as acondenser with respect to the refrigerant systems. Thus, when the firstrefrigerant system operates in defrosting mode, the defrosting operationof first heat-exchange 13 is performed based on a high-temperaturerefrigerant flowing into the first heat-exchanger.

When the first refrigerant system operates in the defrosting mode, thebranch valves 304 and 305 are opened in operation S14. When the branchvalves 304 and 305 are opened, a portion of the water of inlet pipe 301flows into intermediate heat-exchanger 25, and thus a heat-exchangeoperation is performed between the hot water and the first refrigerant.Then, the first refrigerant heat-exchanged with the hot water isheat-exchanged with the second refrigerant to increase the temperaturesof the respective refrigerants. As a result, the reduction of vaporpressures of the refrigerant systems may be minimized.

In operation S15, it is determined whether the defrosting operation isfinished during the defrosting mode of the first refrigerant system.When the defrosting operation is finished, branch valves 304 and 305 areclosed in operation S16. And, in operation S17, the first refrigerantsystem is operated in the previous mode. In this embodiment, the firstrefrigerant system will be operated in the heating mode.

The following embodiment in addition to the previously described twoembodiments may be further performed.

In case where the first refrigerant system is operated in the defrostingmode during the heating mode operation of each of the refrigerantsystems, if branch valves 304 and 305 were in the closed state, thebranch valves are opened. When the defrosting operation is finished, thebranch valves may be closed. On the other hand, when the branch valvesare in the opened state, the branch valves may be maintained in theopened state during the defrosting mode operation of the firstrefrigerant system.

FIG. 4 shows operations included in a third embodiment of a defrostingoperation method of a water circulation apparatus. The third embodimentis similar to the previously described embodiments except that a secondrefrigerant system is also operated in a defrosting mode when the firstrefrigerant system is operated in the defrosting mode.

Referring to FIGS. 1 and 4, water circulation apparatus S is operated ina mode set by a selection of a user in operation S21. Since a defrostingoperation of first heat-exchanger 13 is a focus in this embodiment, acase in which refrigerant systems 1 and 2 are operated in a heating modewill be described.

In operation S22, it is determined whether a defrosting operationcondition is satisfied when water circulation apparatus S is operated inthe set mode. Based on the determination result in operation S22, whenthe defrosting operation condition is satisfied, the first and secondrefrigerant systems are operated in the defrosting mode in operationS23. In this embodiment, the defrosting mode operation of the firstrefrigerant system represents a cooling mode operation of the firstrefrigerant system.

Also, the defrosting mode operation of the second refrigerant systemrepresents the following two cases. First, operation of the secondrefrigerant system is stopped. Second, the second refrigerant system isfundamentally operated in the heating mode, and also second compressor21 is operated at a frequency (e.g., a minimum frequency) lower than anoperation frequency thereof in the previous mode (the heating mode).

In the first case, when the second refrigerant system is operated inheating mode, if branch valves 304 and 305 were in an opened state, thebranch valves are closed. When the branch valves are closed, hot waterwithin a branch pipe is heat-exchanged with a first refrigerant asdescribed in the first embodiment.

In the second case, when the second refrigerant system is operated inheating mode, the branch valves may be in a closed or opened state. Theopening or closing of the branch valves when the refrigerant systems areoperated in the defrosting mode may be adjusted by the methods describedin the previous embodiments. According to the two cases, it may beeasily seen that the reduction of the vapor pressures of the refrigerantsystems is minimized.

In operation S24, it is determined whether the defrosting operation isfinished during the defrosting operation of each of the refrigerantsystems. When the defrosting operation is finished, the refrigerantsystems are operated in the previous mode in Operation S25. In thisembodiment, the refrigerant systems will be operated in the heatingmode.

FIG. 5 shows operations included in a fourth embodiment of a watercirculation apparatus associated with a refrigerant system. The fourthembodiment is similar to the first and second embodiments except that anamount of water flowing into a second water pipe decreases when thefirst refrigerant system is operated in a defrosting mode.

Referring to FIGS. 1 and 5, water circulation apparatus S is operated ina mode set by a selection of a user in operation S31. Because adefrosting operation of first heat-exchanger 13 is a focus in thisembodiment, a case in which the refrigerant systems are operated in aheating mode will be described.

In operation S32, it is determined whether a defrosting operationcondition is satisfied when the water circulation apparatus S isoperated in the set mode. Based on the determination result in operationS32, when the defrosting operation condition is satisfied, the firstrefrigerant system is operated in the defrosting mode and the secondrefrigerant system is maintained in the present operation mode (theheating mode) S33.

When the first refrigerant system is operated in the defrosting mode,intermediate heat-exchanger 25 serves as an evaporator with respect tothe refrigerant systems. When the intermediate heat-exchanger serves asthe evaporator for the refrigerant systems, vapor pressures of therefrigerant systems are reduced as previously described. As a result, acondensing temperature of a second refrigerant is reduced in secondheat-exchanger 23. When the condensing temperature of the secondrefrigerant is reduced, water stored in a water collection tank 34decreases in temperature.

When the water stored in the water collection tank decreases intemperature, water flowing into cooling/heating pipe 63 ofcooling/heating part 5 may decrease in temperature to lower atemperature of an indoor room. Thus, when the first refrigerant systemis operated in the frosting mode in this embodiment, operation of waterpump 36 is changed such that an amount of water pumped into second waterpipe 61 is reduced when compared that the first refrigerant system isoperated in heating mode as in S34. In this case, because an amount ofwater flowing into cooling/heating pipe 63 of cooling/heating part 5 maybe reduced to minimize the temperature reduction of the indoor room.

In operation S35, it is determined whether the defrosting operation isfinished during the defrosting mode operation of the first refrigerantsystem. When the defrosting operation is finished, water pump 36 isoperated in the previous state. Thus, the amount of the water flowinginto second water pipe 61 is recovered to the previous state inoperation S36. And, in operation S37, the first refrigerant system isoperated in the previous mode.

FIG. 6 shows another embodiment of a water circulation apparatusassociated with a refrigerant system. This embodiment is equal to thefirst embodiment except for a structure of an intermediateheat-exchanger and except for a bypass pipe which is disposed inrespective ones of the refrigerant pipes.

In this embodiment, an intermediate heat-exchanger 27 includes a firstrefrigerant passage 271 through which a first refrigerant flows and asecond refrigerant passage 272 through which a second refrigerant flows.

When the first refrigerant system is operated in a cooling mode, a firstbypass pipe 16 for bypassing the first refrigerant discharged from firstcompressor 11 and having a high temperature is connected to outlet-sidepipe 151 of the first compressor and inlet-side pipe 152 of firstrefrigerant passage 271 of intermediate heat-exchanger 27. The firstbypass pipe 16 includes first bypass valve 17 for regulating a flowamount of the first refrigerant.

When the second refrigerant system is operated in heating mode, a secondbypass pipe 28 for bypassing the second refrigerant discharged fromsecond compressor 21 and having a high temperature is connected tooutlet-side pipe 261 of the second compressor and inlet-side pipe 262 ofsecond refrigerant passage 272 of intermediate heat-exchanger 27.

The second bypass pipe 28 includes a second bypass valve 29 forregulating a flow amount of the second refrigerant. The respectivebypass valves 17 and 29 may be opened when the first refrigerant systemis operated in a defrosting mode.

In FIG. 6, a solid arrow line represents a flow of refrigerant thatoccurs when each of the refrigerant systems is operated in heating mode,and a dotted arrow line represents a flow of refrigerant that occurswhen each of the refrigerant systems is operated in cooling mode. Also,a chain line represents a flow of refrigerant that occurs when each ofthe refrigerant systems is operated in defrosting mode.

FIG. 7 shows operations included in another embodiment of a defrostingoperation method for a water circulation apparatus. Referring to FIGS. 6and 7, water circulation apparatus S is operated in a mode set by aselection of a user in operation S41. Because a defrosting operation offirst heat-exchanger 13 is a focus in this embodiment, a case in whichthe refrigerant systems are operated in a heating mode will bedescribed.

In operation S42, it is determined whether a defrosting operationcondition is satisfied when the water circulation apparatus S isoperated in the set mode. Based on the determination result in operationS42, when the defrosting operation condition is satisfied, the firstrefrigerant system is operated in the defrosting mode and the secondrefrigerant system is maintained in the present operation mode (theheating mode) in operation S43.

When the first refrigerant system is operated in defrosting mode,intermediate heat-exchanger 27 serves as an evaporator with respect tothe refrigerant systems and first heat-exchanger 13 serves as acondenser with respect to the refrigerant systems. Thus, when the firstrefrigerant system is operated in defrosting mode, the defrostingoperation of first heat-exchange 13 is performed by a high-temperaturerefrigerant flowing into the first heat-exchanger.

At this time, because intermediate heat-exchanger 27 serves as theevaporator with respect to the refrigerant systems, vapor pressures ofthe refrigerant systems may be reduced to deteriorate cycle performanceof the refrigerant systems or damage to respective ones of thecompressors may occur. To prevent vapor pressure of the intermediateheat-exchanger from being reduced, when the refrigerant systems areoperated in defrosting mode, one of the bypass valves 17 and 29 isopened according to an indoor temperature.

In operation S44, it is determined whether an indoor temperaturedetected by an indoor temperature sensor (not shown) exceeds a firstreference temperature. For example, the first reference temperature maybe about 5° C.

When the indoor temperature exceeds the first reference temperature,first bypass valve 17 is operated to allow the first refrigerant havinga high temperature to flow into the first bypass pipe 16 in operationS45.

On the other hand, when the indoor temperature does not exceed the firstreference temperature, it is determined whether the next detected indoortemperature is between a second reference temperature lower than thefirst reference temperature and the first reference temperature inoperation S46. For example, the second reference temperature may beabout −5° C.

When the detected indoor temperature is between the second and firstreference temperatures, second bypass valve 29 is operated to allow thesecond reference having a high temperature to flow into second bypasspipe 28 in operation S47.

On the other hand, when the detected indoor temperature is less than thesecond reference temperature, first and second bypass valves 17 and 29are operated to allow the first refrigerant having the high temperatureto flow into first bypass pipe 16 and the second refrigerant having thehigh temperature to flow into second bypass pipe 28 in operation S48.

When the high temperature refrigerant is bypassed into one or more ofbypass pipes 16 and 28, because the first and/or second refrigerantincreases in temperature, the vapor pressures of the refrigerant systemsmay be prevented from being reduced.

In operation S49, it is determined whether the defrosting operation isfinished during the defrosting operation mode of the first refrigerantsystem. When the defrosting operation is finished, the opened bypassvalve is closed in operation S50. And, in operation S51, the firstrefrigerant system is operated in the previous mode. In this embodiment,the first refrigerant system will be operated in the heating mode.

As described in the third and fourth embodiments, during the defrostingmode of the first refrigerant system according to this embodiment, thesecond refrigerant system may be operated in defrosting mode or anamount of water flowing into the cooling/heating pipe 63 may be reduced.

In the case where operation of the second refrigerant system is stopped,when the defrosting operation condition is satisfied, first bypass valve17 is always operated to allow the first refrigerant to flow into firstbypass pipe 16.

FIG. 8 shows another embodiment of a water circulation apparatus for arefrigerant system. The water circulation apparatus S may include bypasspipes 16 and 28 and bypass valves 17 and 29.

According to this embodiment, because heat is transmitted to a firstrefrigerant and/or a the second refrigerant by hot water of branch pipe303 and high temperature refrigerant of a bypass pipe, the reduction ofthe vapor pressures of the respective refrigerant systems may be furtherminimized.

The embodiments described herein provide a water circulation apparatusassociated with a refrigerant system.

In one embodiment, a water circulation apparatus associated with arefrigerant system includes: a first refrigerant system including afirst compressor and a first heat-exchanger in which air isheat-exchanged with a first refrigerant, the first refrigerant systemperforming a refrigerant cycle in which the first refrigerant flows; asecond refrigerant system including a second compressor, the secondrefrigerant system performing a refrigerant cycle in which a secondrefrigerant flows; an intermediate heat-exchanger in which the firstrefrigerant is heat-exchanged with the second refrigerant while thefirst and second refrigerant flow; and a water circulation unit in whichwater is heat-exchanged with the second refrigerant while the water iscirculated, the water circulation unit performing a water circulationcycle, wherein the water circulation unit includes a water pipe throughwhich the water flows, a branch pipe branched from the water pipe topass through the intermediate heat-exchanger, and a valve disposed inthe branch pipe to regulate a flow of the water, wherein, when adefrosting operation condition for defrosting the first heat-exchangeris satisfied during heating mode operations of the first refrigerantsystem and the second refrigerant system, the first refrigerant systemis operated in a cooling mode, and water within the branch pipe isheat-exchanged with one or more refrigerants flowing into theintermediate heat-exchanger.

In another embodiment, a water circulation apparatus associated with arefrigerant system includes: a first refrigerant system including afirst compressor and a first heat-exchanger in which air isheat-exchanged with a first refrigerant, the first refrigerant systemperforming a refrigerant cycle in which the first refrigerant flows; asecond refrigerant system including a second compressor, the secondrefrigerant system performing a refrigerant cycle in which a secondrefrigerant flows; an intermediate heat-exchanger in which the firstrefrigerant is heat-exchanged with the second refrigerant while thefirst and second refrigerant flow, the intermediate heat-exchangerincluding a first refrigerant passage and a second refrigerant passage;and a water circulation unit in which water is heat-exchanged with thesecond refrigerant while the water is circulated, the water circulationunit performing a water circulation cycle, wherein a bypass pipebypassing the first refrigerant and the second refrigerant into theintermediate heat-exchanger is disposed at an outlet-side of the firstcompressor or the second compressor, and a bypass valve regulating aflow amount of the refrigerant is disposed in the bypass pipe, wherein,when a defrosting operation condition for defrosting the firstheat-exchanger is satisfied during heating mode operations of the firstrefrigerant system and the second refrigerant system, the firstrefrigerant system is operated in a cooling mode and the bypass valve isopened.

According to the aforementioned embodiments, because the secondrefrigerant heat-exchanged with the first refrigerant of the firstrefrigerant system is heat-exchanged with water, high temperature watermay be obtained. Also, when the indoor temperature is very low, therefrigerant systems may be stably operated and high temperature watermay be obtained.

Also, because the second refrigerant system is operated in heating modeduring defrosting mode operation of the first refrigerant system, thehigh temperature water may be obtained and the indoor room may be heatedusing the high temperature water.

Also, when the first refrigerant system is operated in defrosting mode,because the first or second refrigerant absorbs heat from the hot wateror the high temperature refrigerant discharged from the compressor, therefrigerants may increase in temperature to minimize the reduction ofthe vapor pressures of the respective refrigerant systems.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A water circulation apparatus associated with a refrigerant system,comprising: a first refrigerant system which includes a first compressorand a first heat-exchanger in which air is heat-exchanged with a firstrefrigerant, the first refrigerant system performing a refrigerant cyclein which the first refrigerant flows; a second refrigerant system whichincludes a second compressor, the second refrigerant system performing arefrigerant cycle in which a second refrigerant flows; an intermediateheat-exchanger to perform a heat-exchange operation between the firstrefrigerant and the second refrigerant during flow of the first andsecond refrigerants and a water circulator to circulate water which isheat-exchanged with the second refrigerant while the water iscirculated, wherein: the water circulator includes a water pipe throughwhich the water flows, a branch pipe branched from the water pipe topass through the intermediate heat-exchanger, and a valve disposed inthe branch pipe to regulate a flow of the water, when a defrostingcondition for defrosting the first heat-exchanger is satisfied duringheating mode operations of the first refrigerant system and the secondrefrigerant system, the first refrigerant system is operated in acooling mode and a heat-exchange operation is performed between water inthe branch pipe and one or more refrigerants flowing into theintermediate heat-exchanger.
 2. The water circulation apparatus of claim1, wherein: the valve is opened during the heating mode operations ofthe first and second refrigerant systems and the valve is closed whenthe defrosting condition is satisfied.
 3. The water circulationapparatus of claim 2, wherein operation of the second refrigerant systemis stopped when the defrosting condition is satisfied.
 4. The watercirculation apparatus of claim 1, wherein: the valve is closed duringthe heating mode operations of the first and second refrigerant systems,and the valve is opened when the defrosting condition is satisfied. 5.The water circulation apparatus of claim 1, wherein the valve ismaintained in an opened state regardless of an operation mode of thesecond refrigerant system.
 6. The water circulation apparatus of claim1, wherein when the defrosting condition is satisfied: the secondrefrigerant system is operated in a defrosting mode, and an operationfrequency of the second compressor during the defrosting mode operationof the second refrigerant system is less than that of the secondcompressor during the heating mode operation of the second refrigerantsystem.
 7. The water circulation apparatus of claim 1, wherein: thewater circulator includes an inverter pump regulating a flow amount ofwater pumped into the water pipe, and when the defrosting condition issatisfied, the inverter pump is operated to reduce the flow amount ofthe water pipe than that of the water pipe in the heating mode.
 8. Thewater circulation apparatus of claim 1, wherein: the water circulatorincludes a water collection tank in which the water passing through thesecond heat-exchanger is stored, and the water pipe includes an inletpipe of the second heat-exchanger and an outlet pipe of the secondheat-exchanger, the outlet pipe of the second heat-exchanger isconnected to the water collection tank.
 9. The water circulationapparatus of claim 8, wherein the branch pipe is branched from the inletpipe and joint at the outlet pipe.
 10. The water circulation apparatusof claim 8, wherein the branch pipe is branched from the inlet pipe,passes through the intermediate heat-exchanger, and is connected to thewater collection tank.
 11. The water circulation apparatus of claim 1,wherein: a bypass pipe bypassing the first refrigerant or the secondrefrigerant into the intermediate heat-exchanger is disposed at anoutlet-side of the first compressor or the second compressor, and abypass valve regulating a flow amount of the refrigerant is in thebypass pipe, when the defrosting condition for defrosting the firstheat-exchanger is satisfied, the bypass valve is opened.
 12. The watercirculation of claim 11, wherein the bypass pipe comprises: a firstbypass pipe to allow the refrigerant discharged from the firstcompressor to be bypassed toward the intermediate heat-exchanger, and asecond bypass pipe to allow the refrigerant discharged from the secondcompressor to be bypassed toward the intermediate heat-exchanger, andwherein the bypass valve comprises: a first bypass valve and a secondbypass valve disposed in respective ones of the first and second bypasspipes, and wherein, when the defrosting condition is satisfied, thenumber of opened bypass valves is varied based on an outdoortemperature.
 13. The water circulation apparatus of claim 1, wherein thefirst refrigerant includes R410 a refrigerant and the second refrigerantincludes R134 a refrigerant.
 14. A water circulation apparatus for arefrigerant system, comprising: a first refrigerant system whichincludes a first compressor and a first heat-exchanger in which air isheat-exchanged with a first refrigerant, the first refrigerant systemperforming a refrigerant cycle in which the first refrigerant flows; asecond refrigerant system which includes a second compressor, the secondrefrigerant system performing a refrigerant cycle in which a secondrefrigerant flows; an intermediate heat-exchanger to perform aheat-exchange operation between the first refrigerant and the secondrefrigerant while the first and second refrigerants flow, theintermediate heat-exchanger including a first refrigerant passage and asecond refrigerant passage; and a water circulator to circulate waterthat is heat-exchanged with the second refrigerant while the water iscirculated, wherein: at least one bypass pipe to allow at least one ofthe first refrigerant or the second refrigerant to bypass into theintermediate heat-exchanger, the at least one bypass pipe disposed at anoutlet-side of at least one of the first or second compressor, and atleast one bypass valve to regulate a flow amount of refrigerant in theat least one bypass pipe, when a defrosting condition for defrosting thefirst heat-exchanger is satisfied during heating mode operations of thefirst and second refrigerant systems, the first refrigerant system isoperated in a cooling mode and the bypass valve is opened.
 15. The watercirculation apparatus of claim 14, wherein the at least one bypass pipecomprises: a first bypass pipe to allow the refrigerant discharged fromthe first compressor to be bypassed toward an inlet-side of the firstrefrigerant passage, and a second bypass pipe to allow the refrigerantdischarged from the second compressor to be bypassed toward aninlet-side of the second refrigerant passage, the at least one bypassvalve comprises: a first bypass valve and a second bypass valve disposedin the bypass pipes respectively, wherein a number of opened bypassvalves is varied according to an outdoor temperature when the defrostingcondition is satisfied.
 16. The water circulation apparatus of claim 15,wherein: when an outdoor temperature is greater than a first referencetemperature, the first bypass valve is opened, when the outdoortemperature is between a second reference temperature less than thefirst reference temperature and the first reference temperature, thesecond bypass valve is opened, and when the outdoor temperature is lessthan the second reference temperature, the first and second bypassvalves are opened.
 17. The water circulation apparatus of claim 14,wherein when the defrosting condition is satisfied: the secondrefrigerant system is operated in a defrosting mode, and an operationfrequency of the second compressor during the defrosting mode operationof the second refrigerant system is less than that of the secondcompressor during the heating mode operation of the second refrigerantsystem.
 18. The water circulation apparatus of claim 14, wherein: thewater circulator includes an inverter pump regulating a flow amount ofwater pumped into the water pipe, and when the defrosting condition issatisfied, the inverter pump is operated to reduce the flow amount ofthe water pipe than that of the water pipe in the heating mode.
 19. Thewater circulation apparatus of claim 14, wherein the first refrigerantincludes R410 a refrigerant and the second refrigerant includes R134 arefrigerant.
 20. The water circulation apparatus of claim 14, wherein:when each of the refrigerant systems is operated in the heating mode,the intermediate heat-exchanger serves as a condenser with respect tothe first refrigerant system and an evaporator with respect to thesecond refrigerant system, and when the first refrigerant system isoperated in the defrosting mode, the intermediate heat-exchanger servesas an evaporator with respect to the respective refrigerant systems.